condition mean min max ZT0-3 598.577731 598.577731 598.577731 ZT4-7 683.8213995 683.8213995 683.8213995 ZT8-11 638.701588 638.701588 638.701588 ZT12-15 728.017879 728.017879 728.017879 ZT16-19 711.809795 711.809795 711.809795 ZT20-23 817.5262749999999 817.5262749999999 817.5262749999999